Dental chair.



Patented Oct. 3,J- 899-y A.l P. GuuLu. A DENTAL c HAm. fApplicntion filed July 24, 1899.]

(No Model.)

M'Zredaca:

Fig. 12 is a similar View of the oil-cylinder. 1.0'

chair body and seat.

of a corner of the seat-frame. Fig. l0 is a` Uivi'iltn VSTATES AARON P. conti), or CANTON, onto.'

DENTAL CHAIR.

- .SPECIFICATION forming part of Letters Patent No. 634,084, dated october e, 1899.

. Application filed July 24,1899.

To all whom, it may concern: l

Be it known that I, AARON P. GOULD, a citizen of the United States, residing at Canton,

in the county of Stark and State of Ohio, havel invented certain new and useful Improvements in Dental Chairs; and I do declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to certain novel improvements in dental chairs.

The objects of the invention are to' simplify and improve the construction and increase the convenience of manipulation to the operator and conduce to the comfort of the patient.

To this end` the invention consists in the construction, combination, and arrangement of the several elements ofthe device, as will be hereinafter fully described, and particularly pointed out in the appended claims.

In the accompanying drawings, Figure lis a perspective view of my improved dental ch'air. Fig. 2 is a longitudinal section, partly in elevation. Fig. 3 is a perspective det-ail of the swivel-socket and diagonal brackets. Fig. 4 is a front elevation of the same. Fig. 5 is a detail perspective view. of one of the diagonal brackets. y Fig. Gis a similar view of the cross-head. Fig. '7 is a similar view of the cross-head and rocking lever. Fig. S is a detail perspective view of one corner of the Fig. 9 is a similar-view front elevation, partlyin section, ot' a corner of the chair and seat.- Fig. il isa detail perspective view of the cylinder-head bracket.

Fig. 13 is a vertical transverse section of the same.v

In the drawings the same reference charac- `ters indicate the same parts of the invention.

A denotes the cylindrical pedestal or base, formed with a cylindrical extension a to receive the encompassing socket B, which revolves freely thereon and which may loe locked against rotation by a set-screw. (Not shown.)

arms A2 and A3, to which are secured the parwhich are formed with the parallel grooves Serial No. 724,959. (No mcdeLi y h2 3. I have shownihese diagonal brackets b b formed with a4 lateral stud bx, which extends throughan orifice in the. contiguous parallel arm, and with a horizontal lug h2, which is secured by a bolt to the annular flange of the socket; but it is evident that, if desired, these brackets may be' cast integral with thearms.

E denotes the cross-head, and it is formed with parallel tongues b' b', which have a sliding engagement with the grooves b2 Z22 in the brackets Z9 b. Y I l CV denotes a forwardly -curved arm fulcrumed at its lower enden a pin c, fixed inV the outer ends of the socket-armee.2 and A3, and D denotes a rocking lever fulcrumed on the rod d, transversely fixed in the arrnC, and its lower end is bifurcated and pivoted on the pins e e in the c'ross-headE, while its upper end is pivoted to a rod f, which in turn is -pivoted to a superimposed and rearwardlycurved arm K, the lower end of which is fulcrum ed in the forward end of the lower arm C.

H designates an oil well or chamber fixed withinthe socket B, and within said well is. 'ixedan V oil-cylinder I, in which is mounted a reciprocating plunger E3, the connectingrod f' of which is pivoted to the bracket E4, xed to the arm C.

EA2 denotes "a hydraulic-jack cylinder, the

piston of which is operated by the foot-lever G, there being a suitable valved connection between the cylinder I and the hydraulic-jack cylinder E2, where the oil will he drawn from the oil-Well H and forced into the cylinder I, causing it to raise the plunger E3 and thus elevate the forward end of the arm C, which carries with it the rocking lever D, the lower endof which draws the cross-head E up the inclined grooves in the stationary arms A2 A3, and thus preserves the-relative horizontal arrangement of the free ends-of the arms C and D.

F denotes the seat-supporting frame, which is pivoted on the upper end of the arm K, and it isformed with parallel side rails R to receive the rollers S, mounted in the depending brackets S', formed integral with the chair-seat frame S2. Y

The operation is as follows: AWhen the lever G is reciprocated, the hydraulic-'jack cylinder E2 draws a small quantity of oil from the oilwell Hand forces it into the cylinder' I under l the plunger E3, causingit to rise a short distance in its cylinder l. This movement by the connection with the arm C by the rod j'" causes said arm C to move aboutits fulerumpoint in the socket B, raising'the point of pivotal connection d with the lever D. The lower end of said arm D is in turn pivoted to the cross-head E, which has a sliding engagement with the parallel brackets A2 A3 in the socket B. The lever D will thus be raised at its point of pivotal connection with the arm O, and its lower end, having a pivotal connection with the cross-head at e e, will slide forward and slightly upward in a straight line, as determined by the grooves b2 b2 in the parallel brackets l) D. This movement causes the free end of the lever D to move in the arc of a circle and, being connected by the rod zo f to the arln K, causes said arm to move about its pivotal connection with the arm C, thus keeping the upper end of said arm K and the chair-seat approximately horizontal and parallel with the floor.

The rear end of the chainseat frame is pivoted to the curved arm tof the back-supporting bracket T, the bifurcated arms t t of which are pivoted to the seat -supporting frame by the rivets t2, as shown in Fig. 2.

A spring-actuated lever I is provided with a pawl p, which engages the rack-teeth p', formed on the curved arm f, the operation being such that when the back-supporting arm T is moved forward the seat-*frame S2 will be drawn rearward, and, vice versa, the rearward movement of the back-rest will carry the seat forward.

It will of course be understood that various changes in the form, proportion, and the minor details of construction may be resorted to without departing from the principle or sacriiicing any of the'adva-ntages of this invention. Y

Having thus described the invention, what is claimed, and desired to be secured by Letters Patent, is-

l. The combination in a chair structure, of a base and a body portion; two superimposed arms or levers hinged together at their forward ends, the free end ofthe upper arm connected to the body portion, a swinging bar pivoted intermediate of its ends to the lower arm, a connection between the upper end of Said swingingbar and an intermediate porf tion of the upper arm, a cross-head pivoted to the end of the swingingbar and havinga sliding connection with the base; means for raising and lowering said arms, and means for sustaining said chair-body in the adjusted positions, substantially as described.

2. The combination in a chair structure, of a base and a body portion, an intermediate body-support consisting of two superimposed arms hinged together, one arm being hinged to the base and the other connect-ed with the body portion, a beam or lever pivoted to the lower arm, Ithe lower end of said lever or beam ybeing connected to the base to move in a straight line, a connection between the upper end of said lever or beam and the upper arm to transmit the movement of the lower to the upper arm, means for raising and lowering the said arm, and means for sustaining the body portion in adjusted positions, substantially as described.

3. The combination in a chair structure, of a base and a body portion, a socket revolubly mounted on said base and formed with parallel arms, grooved brackets mounted on said arms, a forwardly-curved arm fulcrumed between said parallel arms, a lever fulcrumedin said curved arm, and a cross-head pivoted to the lower end of said lever and having a sliding engagement with said grooved arms, substantially as and for the purpose set forth.

t. .The combination in a chair structure, of a base and a body portion, a socket revolubly mounted on said base and formed with parallel arms, grooved brackets mounted on said arms, a forwardly-curved arm fulcrumed between said parallel arms, a lever fulcrumed in said curved arm, and a cross-head pivoted to the lower end of said lever and' having a sliding engagement with said grooved arms, a rearwardly-curved arm fulcrumed at its forward en d to said forwardly-curved arm, and a rod pivotally connecting said rearwardly curved arm and the forward end of said lever, substantially as and for the purpose set forth.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

. AARON P. GOULD. Witnesses:

CHAS. R. MILLER, CHAs. M. BALL. 

